Yes, trial/free accounts have the same ability to create rows of fields. If you right click on the field there is an option to "Insert item beside", also if a field is selected there should be a "+" sign to the right that when clicked brings up a vertical toolbar to add an adjacent field.
The only time you might not see this option is using the FormsCentral Desktop application included with Acrobat XI and only if you have never signed in and have not updated the application. If you sign in that will update the application and bring it up to date including all features such as the side by side layout.
There are also 3 fields (in addition to "New page") that can't have others adjacent (these fields are an entire row): Attachment, Ratings scale, and Line. These fields would not show the "+" to the right or have the context menu options.
Let me know if this doesn't resolve this for you.